Process of dyeing.



UNITED STATES- PATENT OFFICE.

OSCAR JAEOK, OF ELBERFELD, GERMANY, ASSIGNOR TO FARBENFABRIKEN OFELBERFELD 00., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

PROCESS OF DYEING.

SPECIFICATION forming part of Letters Patent No. 717,749, dated January6, 1903. Application filed October 2, 1902. Serial No. 125,696. (Nospecimens.)

To aZZ whom it may concern:

Be it known that I, OSCAR J AEGK, doctor of philosophy, chemist,(assignor to the FARBEN- FABRIKEN or ELBERFELD 00., of New York,)residing at Elberfeld, Germany, have invented a new and usefulImprovement in Processes of Dyeing; and I hereby declare the followingto be a clear and exact description of my invention.

As is known, cotton goods dyed with sulfurized substantivecoloring-matters are often subjected to an after-treatment for the purpose of rendering the shades faster or brighter. The steaming operationand the treatment with hydrogen peroxid, with chromates, with sulfate ofcopper, with zinc salts, or the like are well-known operations. Anotherprocess of after-treatment was described in the United States LettersPatent No. 688,999, dated December 17, 1901. treating cotton dyed withsulfurized dyestuffs with alkylating agents.

I have now found a new and valuable process of after-treatment,consisting in treating the goods dyed with sulfurized dyestufis withneutral sulfites, after which treatment it is suitable to expose them tothe influence of the air. The results are remarkable, especially whenusingthosedyestuffs which by theknown process of after-treatment give astill more valuable shadesuch, for instance, as immedial blue 0 R,katigen-indigov B extra and R extra, immedial black V extra, katigenblueblack R, or'the like. The action of the sulfites takes place withgreat facility. It is genorally completed in a short time on working ata temperature of from to 80 centigrade. The resulting shades are mostlydistinguished for great brightness and fastness. They have generally acertain resemblance to the shades obtained bysteaming the dyed cotton inthe presence of alkalies. The low price of the sulfites and the simplemanagement are of great technical value for the new process ofafter-treatment.

In carrying out my process practicallyI can This process consists inproceed as follows: The cotton, dyed with ten per cent. of immedial blueO R, rinsed, and exposed to the air for a short while, is placed in abath containing two grams per liter of neutral sodium sulfite. It ishandled in the dye-bath for half an hour, (the temperature thereof beingkept at about 80 centigrade,) rinsed, and dried. By means of thistreatment the greenish-black shade of the cotton turns into a brightnavy-blue.

The process of after-treatment can also be carried out in the followingmanner: The dyed goods are rinsed and passed two or three times througha bath containing from one to two per cent. of sodium sulfite, (Na SOThe cotton is then squeezed and dried without further rinsing. By meansof this operation the shade is changed in a manner similar to that abovedescribed.

It may, however, be pointed out that the temperature, the duration ofafter-treatment, and'the quantities of sulfites can be varied withinwide limits. On using higher temperatures and larger quantities ofsulfites the after-treatment iseffected in a shorter time.

The process of after-treatment is the same when other sulfurized colorsare used.

The same dyestuffs dyed on other fibers-- for instance, on silkgiveanalogous results.

In the following table the change of shade of some sulfurized dyestuifsof commerce is I indicated.

Shade after the Dyestuffs. Shade after dyeing. treatmentwith sulfite.

Katigen-black S W Jet black having a Bluish black.

greenish tint.

Katigen-indigo B extra. Dull greenish black. Blglght reddish ue.Katigen-indigo R extra. Dull reddish blue-.. Bil-[light reddish ue.Immedial black V extra. Greenish black Dark blue. Pyrogen-blue RGreenishblue-black. Navy-blue. Immedial blue 0 R Greenishblue-black.Navy-blue. Katigen blue-black R.-. Greenish black Dark navy-blue.Katigen blue-black 4 13.. Greenish black Dark blue. Pyrogen-blackGreenish black Dark blue.

Having now described my invention and in What manner the same is to beperformed, In testimony whereof I have signed my What I claim as new,and desire to secure by name in the presence of two subscribing wit- [0Letters Patent, isnesses.

The herein-described process for produein 5 fast shades on the fiber,which process con OSOAR JAECK' sists in treating textile fabrics dyed,with su1- Witnesses: furized dyestuffs with neutral sulfites, sub- OTTOK6NIG,

stantially as hereinbefore described. EMIL PLUMBERG.

